Roller bearing and manufacture thereof



A ril l 1952 p R. R. KILIAN ROLLER BEARING AND MANUFACTURE THEREOF FiledDec 1, 1947 5 Sheets-Sheet l v IN VEN TOR. wf/wdu AT TORNE Y3 R. R.KlLlAN April 1, 1952 ROLLER BEARING AND MANUFACTURE THEREOF 3Sheets-Sheet 3 Filed Dec. 1, 1947 94 I03 I45 88 ms T 44 la;

JNVENTOR. 200 W/(l m BY 1 AT TORNEYS' Patented Apr. 1, 1952 ROLLERBEARING AND MANUFACTURE THEREOF Rudolph R. Kilian, Baldwinsville, N. 1.,assignor 'to Rollway Bearing Company, 1110., Syracuse, N. Y., acorporation of New York Application December 1, 1947, Serial No. 788,987

5 Claims. (Cl. 308217) This invention relates to roller bearings, andmore particularly to retainers for the rollers of a roller bearing andto methods of making such retainers.

One of the principal objects of the invention is toprovide a retainer orcage for use in a roller bearing which is light in weight, which willafiord effective guiding of the rollers for a prolonged useful life, andwhich is adapted for ready and economical quantity manufacture.

Another object is to provide a roller bearing retainer formed ofrelatively light and thin sheet metal in such manner and with suchconfiguration asto possess high strength and rigidity in use While atthe same time its weight is so low as to minimize the centrifugal forceseffective thereon in use.

An additional object is to provide a roller bearing retainer which is soformed from a strip of sheet metal stock that its ends will readilyautogenously weld together without the formation of an objectionablewelding bead requiring a further removal treatment or operation.

It is also "an object of the invention to provide a method ofmanufacturing roller bearing retainers from a strip of sheetmetal ofdesired width which is simple and inexpensive to carry out and whichwill result in the'production of retainers of highly accurate shape andsize.

A further object is to provide such a method including ahardeningtreatment and a subsequent forming operation which impartsdesired rigidity to theretainerand at the same time both counteractsdeformations "such as may occur during the hardening treatment and-alsoassures adequate strength-in the retainer and particularly in the weldedjointstherein.

Another object is to provide apparatus for use in'producin'g retainersfor roller bearings with speed and-high accuracy by successivelypunching and forming receiving pockets for rollers in an advancing stripof sheet stock and periodically cutting off blanks of the proper lengthfor rounding to cylindrical shape and welding to form a bearingretainer.

Still another object is to provide a method of fabricating rollerbearing retainers from sheet metal stock by means of which the ends of astrip of stock are readily welded together to give a re tainer ofaccurately predetermined cylindrical shape and size without theformation of an objectionable welding bead requiring subsequent removal.

of Fig. 3;

Fig. 3 is a view in longitudinal section taken substantially on the line3-3 of Fig. 2;

Fig. 4 is an enlarged detail View in section of a fragment of Fig. 2;

Figs. 5 and. 6 are elevational views illustrating the formation of theblanlrfrom which the retainer of the invention is made;

Fig. 7 is an enlarged detail View of the ends of the blank shown in Fig.6 prior to welding;

Fig. 8 is an enlarged fragmentary view illustrating an intermediatestage of the welding operation;

Fig. 9 is a view similar to Fig. '1 illustrating the e'nds of the blankafter they have been welded together;

Fig. 10 is a View in perspective illustrating apparatus for producingthe blank shown in Fig. 6;

Fig. 11 is a somewhat diagrammatic view partly in side elevation andpartly in vertical section of a portion of the apparatus shown in Fig.10;

Fig. '12 is a sectional view taken substantially on the line |2-i2 ofFig. 11;

Fig. 13 is a fragmentary sectional view of the shearing punch takensubstantially on the line IS- -I'G of Fig. 11;

Fig. 14 is a view in end elevation of the shearing portion of theapparatus of Fig. 10;

Figs. l5, l6 and 17 are perspective views illustrating the apparatus forforming the blank into cylindrical shape, these views illustratingdi-iiercnt stages of the forming operation;

Figs. 18 and 19 are somewhat diagrammatic views partly in elevation andpartly in vertical section illustrating the construction and operationof the apparatus for flaring the retainer; and

Fig. 20 is a view similar to Figs. 13 and 19 illustrating apparatus rforexpanding the retainer to a desired final diameter.

In roller bearings of the type to which the-present invention relates,the retainer or cage serves two important functions. It maintains therollers in proper angularly spaced relation, and it guides theindividual rollers in proper alignment parallel to the axis of thebearing. This latter function is of particular importance for minimumfriction in the bearing as a whole. If the rollers are not accuratelyguided, they may wobble or cock at an angle to the bearing axis insteadof running true, and when this happens the rollers tend to drag in thebearing races and thus give rise to objectionable friction and wear ofthemselves and also of the retainer and the races. Furthermore, as theguiding pockets in the re tainer are thus subjected to increased wearand grow larger in use, there is a tendency on the part of the retaineritself towards eccentric movement in the bearing, which may tend to makethe situation progressively worse.

It is accordingly highly desirable to construct the retainer in suchmanner as to provide guiding surfaces of substantial area for the rollerand thus to distribute any wear or abrasive action present in thebearing over as wide an area as possible and to prevent concentration ofwear in a limited area. This will in turn provide for long resistance towear and thus assure that the rollers will be maintained in properalignment for a long useful life of the bearing. The present inventionprovides a bearing retainer affording these advantages in operation andwhich in addition has substantial advantages from the standpoint ofmanufacturing procedure and cost.

Referring to the drawings, which illustrate a preferred embodiment ofthe invention, Fig. 1 shows a roller bearing retainer constructed inaccordance with the invention and comprising a pair of coaxial butaxially spaced annular rim portions and a plurality of circumferentiallyspaced integral web portions 2| connecting the rim portions andcooperating therewith to form a plurality of pockets 22 for thereception of rollers. As shown in Fig. 1, and also in Fig. 3, the webportions 2| extend substantially parallel to the central axis of theretainer, but the rim portions 20 are flared outwardly with respect tothe web portions 2| through a relatively small angle, for example anangle of the order of substantially 15. In addition, and referringparticularly to Figs. 1 and 4, the web portions 2| have lips 24 formedinwardly thereof to provide guiding surfaces 25 for the rollers 25 inthe adjacent pockets 22. These lips are spaced inwardly from the outerends of the. web portions, as indicated at 27, and their guidingsurfaces 25 are curved about a radius substantially equal to the radiusof the rollers to provide a substantial surface area for guidingengagement with each roller.

Figs. 2 and 3 show a complete roller bearing provided with a retainerconstructed as described. This bearing includes an outer race and aninner race 3| separated by the retainer and the rollers 26, the radialdistance between the two races being substantially equal to the diameterof one of rollers 26. The retainer and rollers are held in positionaxially of the races by means such as split, rings 33 engaged incomplementary retaining grooves 34 in the inner surface of the outerrace 30, as shown in Fig. 3. The retainer is preferably of suchdiameter, as shown in Figs. 2 and 4, that a circle having its center atthe axis of a bearing and passing through the centers of the rollers, asindicated by the dotted are 35 in Fig. 4, will also pass through orclosely adjacent the web portions 2|. With this arrangement, the

4 guiding surfaces '25 of lips 24 will be located primarily andsubstantially completely below this central circle 35 and will thus bein position to exert a highly effective guiding action on the rollers.

The dimensions of the pockets 22 in the retainer are such as to providepredetermined running clearance for each roller in its pocket 22 andparticularly between its pair of guiding lips.

Referring to Fig. 4, it has been found that satisfactory results fromthis standpoint are obtained by curving each guiding surface 25 about aradius equal to that of the roller 26 guided thereby and with its centerof curvature located on the central circle 35 of the bearing but spacedby a small amount, for example, .005 inch, from the center of the rollerwhen the roller is positioned equidistantly from its pair of guidingsurfaces. Thus referring to Fig. 4, the point 40 represents a point onthe axis of roller 26, and the points 3! and 42 represent points on theaxes of curvature of the guiding surfaces 25 adjacent the roller on itsclockwise and counterclockwise sides, respectively, as viewed in Fig. 4.With the roller centrally positioned between its two guiding sur-.faces, as shown in Fig. 4, the portions of the are 35 between point 40and point 4! and between point 40 and point 42 will each subtend a chord01f substantially @005 inch in length, the spacing of the points on thedrawing being somewhat exaggerated for better illustration.

It will aqzordingly be seen that in use, the roller 26 will havesufficient freedom of movement between its guiding surfaces 25, as thusdetermined by the relative spacing of points 4| and 42, to providerunning clearance adequate to avoid binding or other frictionalcontact,and at the same time, this clearance is not so great as topermit appreciable angular movement of the roller, which is thusproperly guided inthe desired parallel relation with the bearing axis.In addition, each pocket 22 is proportioned to provide limited axialclearance for the rollers suficient to compensate for manufacturingerrors but not enough to give rise to undue axial movement oftherollers. For example, in single width bearings, this clearance may beof the order of .005 to .008 inch at each end of the roller, and inso-called double widthbearings, employing rollers of approximately twicethe usual length, this clearance may be substantially .010 inch at eachend of the roller. a

A retainer of the constructionv described shown in Figs. 1 to 4 maybereadily and satisfactorily produced from comparatively light andinexpensive sheet metal stock without sacrificing the desired rigidityand guiding action in use. In general the thickness of the stock dependsupon the size of the retainer, thinner stock being suitable for smallsizes, and an example of a satisfactory material is a low carbon, coldrolled, 17- gage steel substantially .855 inch in width for a bearinghaving fifteen rollers each .500 inch in diameter and .565 inch inlength arranged with their centers .on a circle of approximately 13.35inches in diameter.

Figs. 5 to 8 illustrate different stages in-the manufacture of aretainer of the construction shown in Fig. 1. Referringfirst to Fig. 5,a strip 50 of sheet stock of the desired thickness and width may be fedthrough a progressive die of a punch press or other forming machine, asillus-.

trated' in Fig. 10, which first punches out spaced I-shaped holestherein, as indicated at 5| in Fig. 5, to form the desired rim portions20 and web portions 2!, but with the lips 24 on the webs still in theplane of the strip. For a bearing and. rollers of the above respectivesizes, suitable dimensions for each of these I-shaped holes are .580inch for the distance so in Fig. 5 and .540 inch for the distance 3/ inFig. 5, with each lip 24 being substantially .360 inch measuredlaterally of the strip and .095 inch measured longitudinally of thestrip to assure guiding surfaces of substantial area for the rollers.After the punching operation, the lips are formed out of the plane ofthe strip to the desired curvature already described in connection withFig. l, which may readily be done in a further operation of aprogressivedie.

When the desired number of pockets have been punched and formed for aretainer of predetermined siae, a blank of the proper length severedfrom the strip, such a blank being illustracted at 55 in Fig. 6. Thisblank is then formed to a substantially cylindrical shape, thus bringingthe ends of each of its rim portions 29 into abutting contact, and theseabutting ends 68 are butt welded autogenously as by application ofpressure and electric current. It will be apparout that during thisoperation, a certain amount of metal is lost from the rim ends 553 asthe result of the welding operation, and. also that the rim portionsflow into each other to a certain degree and'thus reduce thecircumference of the retainer as compared with its circumference beforewelding. To compensate forthis loss in circumference, the shearingoperation is so controlled as to leave the rim portions of each blank 55in predetermined excess of the desired final circumference of theretainer, thus providing excess metal to be used during welding.

Referring to Fig. 5, the severing operation is carried out after thenumber of web portions blanked and formed adjacent the leading end ofthe strip is greater by one than the number of pockets to be provided inthe completed retainer. Also, the severing operation is carried outsimultaneously at either side of the last web portion 56 of this countedgroup and at points substantially equally spaced from the web portion56, thus cutting this web portion wholly out of the strip and leavingthe resulting severed rim portions extending at each end of the blankbeyond the adjacent web portions. However, the severing operation doesnot take place at points equidistantly spaced between the web portion 56and the web portions adjacent thereto on either side but instead iscarried out at points closer to the web portion 58, thus providing thedesired excess length in each of the resulting exposed ends 60 of therim portions 28.

Satisfactory results from the standpoint of securing the desired finalaccuracy in the circumference of the retainer have been obtained bycontrolling the excess length in the blank to an amount at each end ofthe rim portion substantially equal to the thickness of the strip stock.This is illustrated in Fig. 6, wherein the distance a-a' represents thedesired circumference of the finished retainer to be formed from theblank 55, but it will be noted that the total length of the blank isequal to the distance b-b, leaving at each end of the blank a length ofstock a-b and a-b which is substantially equal to the thickness of thestock 50. Thus the combined lengths of the projecting end portions ofeach rim portion of the blank will be greater than each length of rimportion between adjacent web portions in the blank, theadditionalmaterial being furnished from the portions of each rimadjacent the web portion 56 which is cut out of the strip.

When the abutting ends 60 of the rim portions of the blank are forcedinto each other during the welding operation, there is some tendency forthe fused metal to be displaced outwardly, and this may cause theformation of an uncle-- sirable welding bead at the Welded joint, It hasbeen found that such bead formation can be controlled by beveling theends of the rim portions in such manner as to leavespace to receive thismetal displaced during welding. Referring par-- ticularly to Figs. 7 to9, Fig. '7 shows the ends of a blank 55 ready for welding. It will benoted that each rim portion 2!] includes an end portion Bilsubstantially at right angles to its length and a portion 6| beveledwith respect to its length and to the portion 68, this beveled portionbeing provided only on the inner corner at each end of each rim. Theangle at which this beveled portion is formed and the amount of materialremoved in the beveling operation is preferably controlled to provide atriangular space capable of receiving slightly more metal than is likelyto be displaced laterally when the ends 60 of the rim portions arewelded together as described.

Thus referring to Fig. 8, which represents an intermediate position ofthe rim ends during welding, as indicated by the electrical connections,it will be noted that the portions Bill of each rim end flow into eachother and at the same time a certain amount of metal from these abuttingportions is displaced laterally as indicated at 65. The triangular spaceformed by the two beveled rim ends 6| is preferably at least sufficientin size to receive this displaced metal 65 and thus to avoid theformation of a laterally projecting welding bead. This desired capacityfor the space 66 has been successfully obtained by beveling the edges 6|at an angle of substantially 45 to the length of the blank and with eachleg of the removed triangular piece substantially equal to the thicknessof the strip stock plus approximately 15% of the stock thickness.

Fig. 9 is an enlarged view of the rim ends after welding, and it will benoted that at the most only a small indentation 66 remains of thetriangular space between the end portions 6| in Fig. 8, the balance ofthis space havingbeenfilled by the metal 65 displaced laterally duringwelding. It will also be noted in Fig. 9 thatnone of this displacedmetal projects inwardly of the rim portions as a head which might causeobjectionable friction against the adjacent end or a roller in thepocket 22 bounded by the welded rim ends.

Figs. 10 to 14 illustrate apparatus for carrying out these punching,forming and shearing or severing operations to produce a blank 55 asdescribed in connection with Figs. 5 and 6. The punch press shownfragmentarily at 10- includes a die-carrying slide H mounted forreciprocating movement with respect to the bolster plate 12 whichsupports the lower dies. The strip 50 of stock is shown as arranged tobe advanced across the press by a feeding unit identified generally as13 and including a pair of feed rolls H and I5 driven from the press bymeans such as a rocker arm 16 and pusher rod 11 to provide a step bystep feed for the stock between working strokes of the press. The upperfeed roll 15 is mounted in bearings 18 mounted for vertical movement inthe feeding unit and normally held in contact with the stock by means ofcompression springs 19.

Referring to Figs. and 11, the stock strip 50 passes from the feedingunit along a track member 84 to and between a block 85 and plate 86carried by a base plate 81 supported by the bolster plate I2. The block85 and plate 86 form lower or female die members, and they are providedwith coincident I-shaped openings 88 adapted to receive a male blankingdie member or punch 90 of complementary configuration for punching theI-shaped holes 5i shown in Fig. 5. This punch 90 is shown as carried bya clamp assembly or block BI which is in turn secured to a plate 92carried by the press slide I2.

The block 85 and plate 86 are also provided with coincident rectangularholes 54 which are adapted to receive a pilot member 95 carried by theclamping assembly 9| in spaced relation with the punch 90-. This pilotmember is of such dimensions as to fit accurately between the adjacentedges of a pair of lips 24 in the stock in order to center the stockaccurately with respect to the blanking dies and also to the dies usedin the forming operation on the lips. As shown in Fig. 11, the maleforming die 38 is bolted to the plate 81, and includes an upwardlyprojecting tongue 99which is adapted to cooperate with the complementaryforming parts of the female die Hi0 carried by the clamp assembly 9i.This female die I96 has its working parts curved at iiiI about theradius of the rollers to be mounted in the finished retainer, as alreadydescribed in connection with Fig; 4, to cooperate with the similarlycurved parts of the tongue 59 for imparting the desired formation to theguiding surfaces of the retainer lips.

Means are provided for supporting the stock above the tongue part 99 ofthe forming die during feeding and for disengaging the formed lips fromthis tongue. A generally U-shaped member is positioned adjacent theblock 85 and includes two side portions I03 and a connecting bridgeportion I04, these side portions I23 being arranged to straddle the maleforming die 58 as shown in Fig. 11. Each side portion IE3 is mounted forlimited vertical movement on a shouldered bolt I95 mounted in base plate81. In addition, each side portion-Hi3 is partially bored out to receivea coil spring Hi8 mounted against a plate i 01 secured to base plate 87by one of bolts I05. The shouldered portions of bolts I95 are of suchlength, as shown in-Fig. 12, as to permit member iii-IE4 to be raisednormally by springs" I06 to a position in which its bridge portion IIMis above the plane of the tongue 9%? on die member 58. Thus betweenstrokes of the press, the stock will ride on the bridge let to preventengagement between the punched holes thereinand the tongue 99. However,when the press'slide descends, the punch 93 and die ii fi will force thestock downwardly and will thus carry member III3-IB4 similarlydownwardly against the pressure of its supporting springs le thedie-member 98 being cut out at I93 to re ceive the bridge I94 as shownin Fig. 11. After theforming stroke is completed and the pressslide'rises, the springs I06 will raise member I03-'I04 upwardly, thusraising the formed lips above the tongue 99 and providing for furtherfeeding of the stock in preparation for the next forming stroke of thepress.

It'will thus be seen that during each stroke of. the press slide II, thepunch 99 and the forming die IUD descend together to carry out blankingand forming operations simultaneously at difierent positions on thestrip. The feed rolls I4 and are so geared and driven, as already described, as to advance the strip the proper dis tance between workingstrokes of the slide, in accordance with the conventional operation ofprogressive dies, but these rolls are released during the actualpunching and forming stroke in order to permit the pilot member 95 toposition the strip with the desired accuracy by entering a previouslypunched but unformed hole 5I in the strip, and thus while the strip isfree, accurately centering it with respect to the die members and IE0 toassure accurate spacing of the roller pockets in the finished retainer.Thus referring to Fig. 10, the feeding unit it includes a lever or crankIII operatively connected with the bearings I8 for feed roll I5 to raisethese bearings against springs I9 when the lever is rotated in clockwisedirection as viewed in Fig. 10. The slide plate 92 carries an arm IIIarranged to engage and depress lever Hi! just before the dies engage thework and thus to effect the desired release of the feed rolls during theactual punching and forming operations.

Figs. 11, 13 and 14 illustrate means for severing a blank from the stripstock after the desired number of pockets have been punched and formedas described. A shearing punch I20 is mounted between two supportingmembers I2I and I22, which are bolted or otherwise secured together asindicated at I23 and provided with a common top member I224. The memberI2I is formed with vertically extending channels for receiving themember I22 and the punch I20,

and the resulting assembly is mounted for vertically reciprocatingmovement relative to the base plate 8?. Referring to Figs. 11 and 14,the member I2I includes legs I25 on either side, and these legs arebored out to have sliding fit with a pair of guide posts I26 mounted inbase plate 81 as shown in Fig. 14. The upper part of member IZI iscounterbored at I2'I to receive bushings I28 having sliding fit withguide posts I25, these bushings being force fit in the counterboresIZ'I. In addition, the member I2I is hollowed at either side andadjacent the guide rods I26 to receive a coil spring I30 and a bolt I3Ithreaded at its lower end into the base plate 87. These bolts IfsI havesliding fit at I32 in the upper portion of member I2I to provide forvertical sliding movement of member ,I2I with members I22 and I24 andthe punch I20: against the pressure of springs I3Ii,- which normallyhold the assembly in its upper position shown in Figs. 11 and 14, thisupward movement of the assembly being limited by contact with the headsof the bolts I3 I; 1

The remainder of the upper'part of the shearing die is formed by twoplates I35 which act as blank holders for the shearing punch I20.Referring to Figs. 11 and 14:, each of these plates I35 has sliding fitwith the punch I2!) and is mounted for limited vertical sliding movementwith respect tothe members I2I and I22. As shown, each plate I35 is inthreaded engagement'with the lower ends of a pair or" shouldered boltsI36 mounted for sliding movement in member I2I or I22. Also, each memberI2I and I22 is partially bored out to receive a coil spring I3! engagingthe upper surface of the adjacent plate I35, these springs normallyholding the plates I35 at their lowermost positions relative tothemembers I2! and I22, in which position they extend below the lower edgeof the punch I 2i) as shown in Fig. 11. With this construction, when themember I2! and the other parts carried thereby are forced down,- wardlyagainst the strip of stock, the plates I35 will engage the stock firstto hold it firmly while the shearing punch I25 continues to descend tocarry out the shearing operation.

Referring to Fig. 13, it will be noted that the shearing punch I 25includes cutting edges I411 arranged transversely of the direction ofmovement of the stock through the dies, and it also includes cuttingedges I4I arranged at an angle to. the cutting edges I45. It willaccordingly be seen that this punch will carry out on the stock thesevering operation indicated in dotted lines at 56 in Fig. 6, with thecutting edges I40 providing the straight ends 53 on the rim portions 25and the angularly arranged cutting edges I 4| similarly providing thebeveled rim end portion BI. Since this operation requires the punchingout of a complete web portion of the stock and parts of the rim portionsconnected therewith, the base plate 81 includes a hole I42 for receivingthis punched out stock. In addition, the female parts of the shearingdie are formed by two spaced plates I45 mounted in a supporting blockI55 on the base plate, and these die portions I45 are provided withedges complementary with the cutting edges of the shearing punch I25, asindicated at I41 in Fig. 11. It will also be noted that the block I46and die plates I45 are formed to provide a guiding track portion I55 forthe stock, including agroove I51 for receiving the downwardly extendinglips on the stock, and plates I I52 overhang these grooves as shown inFig. 14 for maintaining and guiding the stock in proper relation to thedifferent parts of the die. A track I55 (Fig. 10) serves to convey thecompleted blank 55 away from the press.

It will be. understood that the shearing punch I20 should be actuatedonly periodically and not on every stroke of the press, since blanks areout from the stock only after the proper predetermined number of pocketshave been punched and formed therein as described in connection withFig. 6. Accordingly, the press isprovided with operating means for thepunch which will normally be inoperative but which will be controlled bya suitable counting mechanism so as to be actuated only at intervalswhen the proper number of pockets have been formed at. the advancing endof the strip.

Referring to Figs. 10 and 11, the punch assembly is at such a heightbelow the slide plate 9.2: that it will not come in contact with theslide on'its down, stroke. A bellcrank lever including arms I59 and IBIis mounted for rocking movement on the vertically arranged stud I52carried bya plate I53 bolted or otherwise secured to the plate 52. Thelever arm IE5 is so arranged that it can be swung into a positionbetween the plate 92. and the top I24 of the shearing punch assembly, inwhich position it will actuate the shearing punch on the down stroke ofthe slide. A coil spring I54 is arranged in such manner as: to hold thelever arm I65 normally out of engageable position with the punchassembly. Inorder to swing the lever arm I65 into its operativeposition, means such as a solenoid I55 may be mounted on the press slideas shown in Fig. 11, with its plunger I65 so connected with the leverarm I6I that when the operating coil ofthe solenoid is energized, itsplunger will swing the lever arm IGI in such direction as to move leverarm I60 against, spring I64 and into operative position relative to thepunch assembly. In the operation of the apparatus, a suitable countingmechanism I61 is connected with the press in. such manner that it willenergize the solenoid coil at intervals after the proper number ofstrokes of the press required for punching and forming the desirednumber of pockets in the strip. During the other strokes of the press,the solenoid will be deener'gized, and the spring I54 will hold leverI55 in its inoperative position to prevent actuation of the shearingpunch.

After the complete, blank has thus been produced as described inconnection with Fig. 6. and Figs. 10 to 14, it is formed into the propercylindrical shape, and Figs. 15 to 17 illustrate apparatus. for carryingout this forming operation. The punch press shown fragmentarily at I15includes a reciprocating slid I1i and a bolster plate I12. The slide I1Icarries the upper or male members of the. forming die I15, and, theplate I12 supports the female dieunit I16. These dies are so constructedthat they are eflective to form a straight blank 55 into cylindricalshape in three successive steps.

Referring first to Fig. 15, it will be noted that the male die I15includes a semi-cylindrical front portion I and a cylindrical rearportion I81, each of which is provided with a groove I82, I83,respectively, for receiving the lip portions 24 of the retainer blank.The female die unit I16 includes a semi-cylindrical front portion Iadapted to receive the male die, portion I80, and two guide pins I86 aremounted therein for cooperation with receiving bores H31 in male dieportion I80. The female die unit also includes a cylindricallycurvedrear portion I881, but this portion I88 has an angular extent ofonly approximately 90 and the remainder of this part of the .die is cutaway as indicated at Hi9.

Fig. 15 shows the position of the parts following the first step of the.forming operation. For this step, the blank 55 is inserted in the femaledie portion I88, and the press is operated to carry out a forming strokeof slide ill. The result of this stroke is to impart a cylindrical curveto a portion I90 at one end of the blank substantially equal toone-quarter of its total length, as a result of the 90 curvature of dieportion [88, the remainder of the blank being received in the. cutawayportion IB9 of the die.

Following the step of Fig. 15, the blank is turned, around, and itsopposite end is inserted in die portion I88 and the Press is againoperated. Fig. 16 shows the position of the parts after completion ofthis second forming stroke, and it will be seen that a cylindrical curvehas been imparted to the quarter portion E5! of blank 55 at the endopposite curved portion the. The blank is then moved to the front of thefemale die. unit and centered with respect to die portion I55, and thepress is operated a third time. Fig. 17 shows the positions of the partswith the press at substantially lower dead center of this third form ingstroke, and. it will be seen that the semicylindrical die. portions I85and I35 have cooperated to impart a semi-cylindrical form to theintermediate portion of blank 55, thus.bringing the ends of portions I55and NH together and completing the forming operation.

The formed blank is now ready for the welding operation, as alreadydescribed in connection with Figs. 7 to 9. It has also been. foundadvantageous to subject the welded blank to a case hardening treatment,such as a cyanide treatment, sufficient to produce a hardened surfaceto. a depth of the 11 7 order of approximately .002 to .003 inch. Afterhardening, the retainer is ready for the flaring operation inwhich therim portions 20 are flared outwardly with respect to the web portions 2|as described in connection with Figs. 1 and 3, and Figs. 18 and 19illustrate apparatus suitable for carrying out this operation.

Referring to Fig. 18, the retainer is first clamped within a cylindricalfemale die 200 of the desired inner diameter with which the web portions2| are to conform in the finished retainer. This die includes two halfportions pivotally connected together for clamping action, and it isflared outwardly at its upper end 20! at the desired angle to itscylindrical portion 202, for example an angle of the order ofsubstantially .15". The lower end of the die 200 is counterbored at 203to receive one flared rim portion of a retainer during flaring of itsother rim portion, as will be described. A male flaring die or punch 205is mounted for reciprocating movement relative to the die 200, and itincludes a tapered flaring portion 206 and a cylindrical pilot portion201. The diameter of this pilot portion 201 is controlled to besubstantially equal to the inner diameter desired for the web portions2| of the finished retainer, and the axial length of the pilot portionis sufficiently short so that it will not come in contact with the lips24 of the retainer during flaring.

Fig. 19 illustrates the flaring dies in their flar ing relation. Asshown, the male die or punch 205 has entered the retainer and itsbeveled portion 206 has formed the rim portions 20 out wardly to thedesired flared shape. At the same time, the portions 21 of the webs 2!between lips 24 and rims 20 are gripped between the pilot portion 201 ofthe punch and the cylindrical, wall 202 of the female die. In the nextstep of the flaring operation, the male die is lifted and the female diereleased, and the retainer is then turned over to flare its other rimportion. During this step, it will be seen that the rim portion alreadyflared will be received within the counterbored portion 203 of thefemale die and will thus be protected during the other flaringoperation.

This flaring operation and the resulting flared construction of theretainer afford substantial advantages in the practice of the invention,one of the most important being to add rigidity to the retainer as awhole and thus to increase its resistance to deformation under stress inhandling and in operation. As a result, the finished retainer is foundto possess rigidity substantially equal or superior to that of retainersformed of heavier stock without a peripheral flare or flange. At thesame time, the light weight of the retainer of the invention minimizesthe centrifugal force effective thereon in operation and thuscorrespondingly reduces stress thereon as compared with retainers ofthicker and heavier stock.

Another advantageous result of the flaring op eration is the substantialelimination of distortions such as often result from the cyanide orother hardening treatment. With the flaring dies of the constructionshown in Figs. 18 and 19, the cylindrical pilot portion of the male dieenters the retainer first and thus rounds it out before flaring begins.In addition, as described in connection with Fig. 19, this pilot portionalso forces the outer ends of the web portions 2! to conform to thecylindrical portion 202 of the female die. Furthermore, the flaring ofthe rim a 12 portions has the additional effect of holding these webportions in the desired cylindrical alignment thus imparted to them bythe pilot portion of the male die, providing a substantially permanentcorrection of such deformation as may previously have been presented.Still another advantage of flaring the rim portions following welding isthat it provides a positive test of the strength of the welded joint,and if a weld is imperfect it will tend to break under the stress offlaring. Thus the welded portions of the rims serve as test sections forthe retainer, and if the joints hold during flaring, this assures properstrength therein for the subsequent use of the retainer.

It is sometimes found that the diameter of the retainer after weldingmay vary from the desired dimension, such variation being due to one ormore of several causes including accumulation of small pitch variationsin the initial blanking and forming operations, variable stretch of thematerial during forming operations, and varying amounts of metalconsumed in welding. The total of these variations is usually not large,for example within a range of plus 0.010 inch and minus 0.050 inch ofthe desired final diameter, but it may cause the retainer to beundesirably loose or tight in the finished bearing and is preferablycorrected for as now described.

If the retainer is slightly too large,for ex ample up to approximately0.010 inch too large in diameter, the desired correction will be madeduring the flaring operation already described in connection with Figs.18 and 19. When the female flaring die200 is closed on the retainerunder high pressure, the rim portions 20 will be squeezed to the desireddiameter. Then when the male die 205 is operated, it causes the retainerrims to stretch outwardly and to set in their resulting flaringcondition, thus holding the remainder of the retainer to the desiredfinal diameter. It should also be noted that the flaring operationtendsto produce some reduction in the width of the pockets 22 in theretainer but with the initial width of the pockets controlled as statedto provide a clearance of from .006 to .008 or .010 inch at each end ofthe roller, this reduction will not undesirably affect the properrunning clearance for the rollers.

If the retainer is slightly too small, for 'example up to approximately0.050 inch too small in diameter, it may be stretched to the desiredfinal diameter without loss of its other properties, and Fig. 20 showsapparatus suitable for such a stretching operation. The undersizedretainer is supported in an annular female die 2 [0 provided with aninternal shoulder or counterbore 2 of approximately the desired outerdiameter for the retainer. A cylindrical male die or punch 2I2 ismounted for reciprocating movement with respect to die 2"), and itincludes a tapered pilot portion 215 at its lower end. The punch 2I2 isof such diameter that when it is inserted in the retainer, it willengage the inner edge of lips 24 and act through these lips to expandthe rim portions 20 to the desired final diameter.

When all the above operations are completed as described, the retainerwill have the appearance shown in Fig. 1 and the characteristicsdescribed in connection therewith, and it will be ready for assembly ina ,complete bearing as shown in Figs. 2 and 3. The retainer will belight in weight but will possess rigidity adequate to resist deflectionor deformation incident to normal stresses in handling and use. Inaddition, the lips of the retainer form guiding surfaces of substantialarea for the rollers efifecti-ve to minimize cocking or wobbling of therollers or other relative movements in the bearing tending to createfriction, thus promoting a long useful life for the bearing. It willalso be apparent that these retainers can be readily produced at lowunit cost in any desired sizes to fit bearings and rollers of any lengthand diameter, by suitable control of the relative sizes and spacing ofthe dies shown in Figs. to 20.

While the method, article and apparatus herein described constitutespreferred embodiments of the invention, it is to be understood that theinvention is not limited to this precise method, article and apparatus,and that changes may be made therein without departing from the scope ofthe invention which is defined in the appended claims.

What is claimed is:

1. The method of manufacturing a retainer of predetermined circumferencefor a roller bearing which includes the steps of punching spaced holesin a strip of sheet metal to form a blank having rim portions connectedby spaced web portions defining pockets therebetween for the receptionof rollers and with said rim portions extending at each end beyond theadjacent one of said web portions, forming said blank into cylindricalshape, autogenously welding together the abutting ends of said rimportions under controlled conditions of heat and pressure providing saidpredetermined circumference after said welding, and then flaring saidrim portions radially outwardly relative to said web portions to stiffensaid retainer and to assure a substantially cylindrical configurationthroughout said web portions.

2. The method of manufacturing a retainer of predetermined circumferencefor a roller hearing which includes the steps of punching spaced holesin a strip of sheet metal to leave rim portions connected by spaced webportions defining pockets therebetween for the reception of rollers,periodically severing said strip to form blanks each including apredetermined number of said web portions equal to the number of saidpockets to be provided in the completed retainer, said severingoperation being performed simultaneously at either side of the webportion in said strip adjacent said severed blank and at points equallyspaced from said web portion but closer thereto than to the web portionson either side thereof to leave the rim portions of said blank withtheir lengths in predetermined excess of said predeterminedcircumference for said completed retainer, beveling one corner of eachof the resulting severed ends of said rim portions simultaneously withsaid severing operation, forming said blanks into cylindrical shape,autogenously welding the abutting ends of the rim portions of each saidblank under conditions of heat and pressure providing for reduction ofthe length of each said rim portion to substantial equality with saidpredetermined circumference and for displacing said excess length ofmetal into said beveled corners, and then flaring said welded rimportions radially outwardly relative to said web portions to stiffensaid retainer and to maintain said predetermined circumference andcylindrical shape through said web portions.

3. The method of manufacturing a retainer of predetermined circumferencefor a roller bearing which includes the steps of punching spaced holesin a strip ofsheet metal to leaverim. portions connected by spaced webportions defining pockets therebetween for the reception of rollers,severing said rim portionsfrom the remainder of said strip at pointsspaced'between adjacent web portions such that the length of each saidrim portion is in predetermined excess. of said predeterminedcircumference for the completed retainer, forming said severed stripinto cylindrical shape, autogenously welding together. the abutting endsof said rim portions under conditions of heat and pressure providing forreduc tion of said length of said rim portions to substantial equalitywith said predetermined circumference, and then flaring said rimportions radially outwardly relative to said web portions to stiffensaid retainer and to maintain said predetermined circumference andcylindrical shape through said web portions.

4. A roller bearing retainer of the character described formed from aflat strip stock and comprising a pair of axially spaced coaxial rimportions, a plurality of web portions connecting said rim portions anddefining a cylindrical shape, said web portions being angularly spacedto form pockets therebetween for the reception of rollers, said rimportions being flared in radially outwardly diverging relation withrespect to said web portions at a relatively small angle with respect tothe central axis of said. retainerto stiffen said retainer in saidcylindrical shape, each said rim portion having the ends thereofautogenously welded together in abutting relation and with the weldedjoint therebetween flared-integrally with the remainder of said flaredrim portion, and lips on said web portions formed inwardly thereof toprovide guiding surfaces for rollers in said pockets.

5. In a roller bearing including an inner and outer race and a pluralityof rollers positioned between said races, a retainer formed from flatstrip stock and comprising a pair of axially spaced coaxial rimportions, a plurality of web 5 portions connecting said rim portions anddefining therewith a cylindrical shape, said web bortions beingangularly spaced to form pockets therebetween for the reception of saidrollers, the diameter of said retainer measured across said Web portionsbeing approximately equal to the diameter of a circle passing throughthe centers of all of said rollers, said rim portions being flaredradially outwardly relative to the adjacent ends of said web portionsthrough a relatively small angle with respect to the central axis ofsaid retainer to stiffen said retainer and to maintain said cylindricalshape thereof through said web portions, each said rim portion havingthe ends thereof autogenously welded together in abutting relation andwith the welded joint therebetween flared integrally with the remainderof said flared rim portion, lips on said web portions formed radiallyinwardly thereof to provide cylindrically curved guide surfaces for saidrollers, the radius of curvature of said uide surfaces beingsubstantially equal to the radius of said rollers, and said webs beingangularly spaced by an amount sufficient to provide guiding clearancebetween each said roller and the adjacent pair of guiding lip surfaces.

RUDOLPH R. KILIAN.

(References on following page) Number Name Date Andren Aug. 16, 1932Mitchell Jan. 17, 1933 Gibbons Dec. 19., 1933 Hermann Oct. 8, 1935 BrownApr. 21, 1936 Brown Apr. 21, 1936 Annen Mar. 29, 1938 Beck June 28, 1938McGee May 21, 1940 Frauenthal Aug. 25, 1942

